Rotation device for drilling mechanisms



D. K. DOVELI,

ROTATION DEVICE FOR DRILLING MECHANISMS Filed J y 29,

flUDLEY m Dot/ELL BYM W,

HTT'

Patented Jan. 22, 1 935 nnvron- Fon DRILLING. V MECHANISMS Dudley K.DovellfEl fPjaso, Tex., .assignor to 8111- I livan Machinery Company, acorporation of.

Massachusetts f Application July 29.1930, Serial No. 471,581

- 3 Claims;

Thisinvention relates to drilling mechanisms and more particularly toimproved .meansfor cona trolling drill steel rotation-of a fluidpressure actuated hammer type drill t In various types of drillingmechanism, especially of the pneumatic hammer type, the drill steel isintermittently rotated by the hammer'piston through a pawl and ratchetmechanism cooperating with a rifle bar and nut. In certain.

types of drilling mechanisms, such as stopers, it is particularlydesirable to be able todisconnect the drill steel rotating mechanismwhile permitting continued reciprocation of the hammer piston. I '1 Itis an object of my invention to provide improved means whereby the drillsteel rotating mechanism may be variably controlled. while permittingcontinued reciprocation :of. the hammerpisto-n. A further and morespecificobject is to provide improved meansfor releasing the ratchet ofthe pawland ratchet rotating mecha nism and in the specific aspect'ofthe invention to provide an arrangement whereby the ratchet. may bereleased by rotating a suitable member. to permit a pawl or othersuitable stop element to be moved out of the path of the ratchet when itis desired to stop steel rotation.

Other objects and advantages will be mor'eap parent to those skilled inthe art and. modificae tions of my invention will likewise be readilyap--' parent to such persons, from the following description of theaccompanying drawing, in Which,-

Fig. 1 is a side elevation of a stoper type of drilling mechanismequipped with an illustrative form of the improved rotation controlmeans;

Fig. 2 is an enlarged transverse section taken substantially on the line2--2 of Fig. 1;

Fig. 3 is a fragmentary longitudinal section through the drill motorshowing the ratchet mechanism and hammer piston; and

Figs. 4 and 5 are elevational views of the cam for controlling theoperation of the ratchet mechanism.

While I have shown my improved rotation control in connection with adrilling mechanism of the stoper type generally indicated at 1, it willof course be understood that the same may be applied to various othertypes of drilling tools whether suitable for rock drilling or otherwise,although for various reasons the improved ratchet control isparticularly applicable to a stoper type of hammer drill provided with asuitable feed, generally indicated at 3, and which 5 may be of the fluidactuated type or of any other type whereby a drill steel 4 carried in ausual chuck housing 5 may be fed with the drilling motor. The motor isof the conventional piston hammer type having a hammer piston 6'provided with' a fluted striking .bar '7, the flutes of which engage asuitable nut of the chuck whereby. rotation of the pistonwilleffect'rotationof the chuck and in turnrot'ation of i drill steel 1in.any usual manner. To effect pistonr'otation an internal ratchet 8,journaled 10 inithe rear headof themotdrgcooperates with a seriesofspring pressed pawls 9. .These pawls are pivotallysupportedinasuitable' head 10 which hasa bar 11 from which a rifleLbar 12 extendsforicooperation with a spiralnut 13 secured in a bore of the piston 6;Assuming the ratchet 8v to. be held stationary, .rearwardmovement of thepistonyficau'ses it to: be'partially rotated due to rifle bar 12 beingheld stationary by engagement of the pawls with thefixed ratchet. Thispartial rotation of the piston is transmitted to the drill ste'el fromstriking bar 7 but upon forward movement' of-.the piston the rifle bar12 is partially rotate'dina counterclockwisedirection, as viewed in Fig.:2', during whichatime the pawls 9*s1ipover the internal .ratchetteeth... As isiusual, successive'reciprocating movements of the pistonefiects a constant step by step rotation'of the drill steel. In the.type of motor herein disclosedja hollow distributing sleeve valve 14 isprovided for effecting the'necessary fluid distribution to actuate thepiston .6 and through. which bar, 11 extends- V 1' 7 To release theratchet 8, thereby permitting the rifle bar 12 to oscillate duringreciprocation of the piston 6 and hence not transmit any rotationthereto, the ratchet is provided with a peripheral groove 15 one endshoulder ofwhich is adapted to be engaged by a radially movable. stoppawl 16 suitably pivotally supported in a relatively wide recess 18 ofthe drill head, whereby when the stop pawl is moved to the other side ofits wide recess, as shown in dotted lines in Fig. 2, the ratchet 8 mayfreely rotate 'as the rotation pawls are successively oscillated.

The means for holding the control or stop pawl 16 in operative positionfor effecting steel rotation comprises a pin 20 pressed into engagementwith pawl 16, as by a cam 21 having a flat portion 22 which rides uponthe inner end of pin 20. The cam 21 is actuated by any suitable meanssuch as a handle 23 and in addition is provided with a recess 24 forengagement with the reduced end of a lock pin 25. This lock pin is heldin position by a leaf spring 26 suitably secured at one end on the drillcasing while the 55 whereby no rotation will be transmitted to the steelalthough the piston may continue'to reciprocate To prevent possiblereverse rotation of the ratchet ring during steelrotation, a. pivotedspring-held stop pawl 30 engages a notch 31' in the ratchet periphery.This pawl isinclined so as to resist reverse rotation but pen-nitforward rotation when the other stop pawl 16 is-released, and yet willdrop into notch 31 when pawl 16 is moved from its. inoperative to.operative. position. Groove 15, is of suificient length to. permitproper clearancefor the swinging ofipawl 16. 1

From the foregoingdescription it. willbe readily apparent that drillsteel rotation may. be discontinued during continued reciprocation ofthe hammerpiston. merelyzbylifting lock pin 25 and rotating handle23,.in a clockwise directionwhereupon-the cut away portion 33' of cam21; permitsholding pin 20 12011110178 away. from pawl 16 to permit it tomove to it's; inoperative position. "To reestablish steel rotationxthehandle 23;:ls :rotated. downwardly to the position shown. in Fig. 2therebymoving pin 20 and pawl 16 into the position as shown, although itwill. of course be :seen that.

if the peripheral .groove=15. doesnot happen. to: be in suchranangularposition as to permit pawl: 16 to drop therein, due itothe ratchet 8,having. been rotated, the pawl 16 will simply ride upon the periphery.of the ratchet until groove l5yis finally rotated around to thenecessary position-where pawl 16 will drop During such. :a condition theoperator would merely maintain alight pressure upon the handle 23until'the grooveisengaged', whereupon the lock pin 25'wouldautomatically'fall into recess2i and positively hold the device inoperative condition. vAt the-same time reverse pawl 30 willdropinto'notch :31.

While there is in this application'specifically described one form whichthis inventionmay assume inpractice, it-will be understoodthat this formofthe same is shown for purposes of'illusholding members, one arrangedto engage one of said shoulders and. the other to engage the other ofsaid shoulders and each rotatable on an axis spaced from the axis ofrotationof said pawl and ratchet elements into its shoulder engagingposition, and means for causing said members concurrently to. have.engagement, with the shoulders with whichthey-respectively cooperate.

42,111 a hammer drilling mechanism, tool rotation mechanism including aratchet, means for rotatably supporting said ratchet, means forpreventing rotation of. said ratchet including relatively opposedshoulders adjacent the periphery oixsaid ratchet, pivoted pawlsrotatableon axes spaced. from..,the axis-of ratchet rotation and swingable' -onsuch axes, one into engagement with oneiof 'saidshoulders andthe otherwith the other of saidrshoulders, and also swingable out of engagement.with said shoulders, and means for at will holding one. of said elementsagainst swing-ingoutof "engagement with its cooperating shoulder. I 1 e3. .In ahammer drillingmechanism, tool rotationmechanism. including aratchet, means for rotatablysupporting said ratchet, means forpreventingv rotation of. said ratchet including relatively opposedshoulders adjacent the periphery ot .sai'dratchet.,.pivoted pawlsrotatable on axes spaced: from the. axis of ratchet rotation andswingable. on. such axes,..one,into engagement with oneaoflsaid.shoulders and the other with theother: ofsaid shoulders, andalsoswingable out of engagement with said shoulders, and a 'camforipositively swinging one of said pawls into engagement with itscooperating shoulder and locking it there.

. DUDLEY K. .DOVELL.

